How do I limit articles users can edit using k2?

Hello,

I want registered users on my website to be able to publish articles, but I don't want them to alter in anyway articles published by the administrator. I have tried changing user permissions but it seems that I can either grant or not grant them rights, can't find anyway to limit it.

What can I do?

You have "Viewing Access Levels" in user manager and you have Set Permissions option in each article and category.

Maybe you need to create one more user group to be able to control that efficiently. Read joomla documentation that is not template or extension related subject